Adjusting device for sharpener for tobacco cutter



April 15, 1958 M. POLLMANN ADJUSTING DEVICE FOR SHARPENER FOR TOBACCO CUTTER Filed Nov. 25, 1953 ADJUSTING DEVICE FOR SHARPENER FOR TOBACCO CUTTER Max Pollmann, Hamburg-Bergedorf, Germany, assignor to Kurt Korber & Co., K.-G., Hamburg-Bergedorf, Germany Application November 25, 1953, Serial No. 394,459

Claims priority, application Germany December 19,1952

1 Claim. (Cl. 146-117) The present invention relates to improvements in tobacco cutting machines and is particularly concerned with an adjusting device on a tobacco cutting machine with a cutter head rotating in front of the mouthpiece and with a reciprocating grinding device rotating in front of the head.-

Before cutting of the tobacco is begun with tobacco cutting machines, especially with drum cutters, in which the tobacco is to flow out of a mouthpiece in the direction of the cutter drum, the knives mounted on the periphery of the cutter drum must be brought to a definite distance in relation to the mouthpiece, that is to the forward edge of the lower mouthpiece jaw, as the counter knife for the rotating cutters. This adjustment is important since the quality of the tobacco depends on the nature of the cutting. it is also necessary that this separation can be adjusted in the most exact manner and the adjustment held.

It is known to place the cutter drum and grinding device on a common support frame and to move this frame to and from the mouthpiece by a crank drive through a small lateral rocking of the crank over the dead centre position and thereby to regulate the distance between the mouthpiece and cutter drum. This method of construction is disadvantageous owing to three in-line pivots, since the play in these pivots together with the play in the drum shaft bearings are additive. In this manner it is only possible with difficulty with continuous tobacco feed to adjust and retain precise separation between the cutter knives and the tobacco mouthpiece and particularly during the operation.

This disadvantage is eliminated according to the invention by the fact that preferably oneach roller bearing in front of the end of the cutter drum on the connecting line between the centre points of the drum and of the grinder means, an adjustable diamond is provided at the level of the cutter knife edges, of which the point adjustment determines the spacing of the cutter knives from the counter edge on the under jaw of the mouthpiece. The diamond points thus coincide with the cutter knife edges. By a small adjustment of the diamonds the outer position of the cutter knives and thereby the overall diameter of the cutter drum is determined. On the other hand the spacing between the cutter'knives and the tobacco mouthpiece outlet is likewise determined.

It is also possible to adjust the diamonds individually so that also a possible oblique positioning of the knives in relation to the mouthpiece can be corrected.

The features of the present invention are shown by way of example on the accompanying drawings, wherein:

Fig. l is a plan view partly broken away of a cutter drum and a grin-ding device lying in front of it, showing the manner in which the grinding wheel dressing tools are located and positioned in alinement with the edges of the cutting drum.

Fig. 2 shows diagrammatically a side view of Fig. 1, and

nited States Patent 4, 2,830,634 Patented Apr. 15, 1958 Fig. 3 is an enlarged vertical cross-sectional view of a diamond holder taken on line 3-3 of Fig. l.

The tobacco cutting machine generally includes a supporting frame 1 having a shaft 2 for rotatably supporting a cutter drum 3 having a series of circumferentially spaced knives 4. The shaft 2 is supported by bearings 1' at each end of the frame 1 and said bearings may be of the plain or anti-friction type. The cutter drum is driven from a suitable power source in the usual manner or,

if desired, may be coupled to another source such as the drive motor which serves to deliver the tobacco in the hopper of the tobacco cutting machine. The cutter knives 4 and drum are movable toward the mouthpiece of the cutting machine in a manner well known in the art as shown in British Patent 573,416 to S'chrieber, November 20, 1945. If desired, the feed can be of a continuous slowly progressive or step by step type actuated by the rotary movement of the drum. A bracket 5 (Figs. 1 and 3) is provided on the support frame 1 adjacent the ends of the cutter drum, each bracket carries a sleeve 6 which is threadedly received in a correspondingly threaded opening in the bracket 5 to permit the sleeve 6 to be adjusted by means of a pin spanner or key which engages within suitable apertures 7 in the sleeve 6. A diamond holder in the form of a shouldered stud 8 is located in the sleeve 6, and can be rotated when the surfaces 9 are engaged by a wrench. A diamond is secured to the forward end of each shouldered stud 8 in known manner and two lock nuts 11 are provided at the rear end which are tightened to such an extent that the diamond holder 3 can still rotate. The diamond holder 8 is inclined to a horizontal plane extending through the drum axis 2 and an adjacent grinding wheel axis 19 at an angle or of preferably 5.

A slide 12 also runs on guide rails 12a on the drum support frame 1 preferably parallel to the drum axis, which slide is, for example, operated by a crank drive 13, 14. The crank 14 is connected with a shaft 15 which is rotated in known manner to cause a reciprocation of the slide 12. A cross slide 16 moves on the slide 12 at right angles to the latter and carries an electric motor 17. The cross slide 16 is adjusted by means of a crank 18 having a screw feed connection 24 with the slide 12. The shaft ends 19 of the motor carry two grinding wheels 20. The motor with the grinding wheels can be moved to and from the cutter drum by a wheel 18 through a spindle 24 according to the known step feed devices on machine tools; a crank handle 18a on the wheel 18 permits the reciprocation to be also effected by hand.

The mouthpiece jaws 22 and 23 lie on the opposite side of the cutter drum in the machine frame 21, whereby the mouthpiece jaw 22 serves as a counterknife for the knives 4 on the cutter drum. The counterknife 22 is preferably fixedly connected to its machine frame section 21. The upper jaw 23 does not comeinto contact with the rotating knives 4 and can move up and down as shown in the British Patent 573,416 to Schrieber, November 20, 1945. It is of no importance for the present invention Whether the drum support frame 1 is fixedly connected to the machine frame 21.

The rotary path of the knives on the cutter drum is determined by the adjustment of the diamonds. It has proved advantageous to retain a spacing of preferably 0.05 mm. between the forward knife edges and the counterknife edge. At the same time the feed of the grinding wheels is determined by the adjustment of the diamonds; they serve moreover for trueing the two grinding wheels 20.

In operation, the frame 1 is adjusted toward the main frame 21 and with respect to the discharge mouthpiece 2223. The knives 4 are manually brought into engagement with the counter knife 22 in succession. initial step in adjusting the knives and after this has been done, the frame 1 is moved slightly so that a strip of metal of about 1 millimeter in thickness may be placed between the edge of the knives 4 and the knife 22. After the frame 1. has been adjusted as above the carriage 12 is adjusted by the hand wheel 18 to move the grinding discs 26 toward the cutting edge of the knives 4. The diamond dressing tool It! is advanced slightly at one side of the drum in order to dress the grinding wheels 20 such that they are both the same diameter. If the carriage 12 is now moved to the end of the cutting knife, both discs will engage at the same time. The other diamond dressing tool it) is adjusted until it touches the periphery of its grinding wheel and the drum 3 is now rotated and the motor 17 is energized to sharpen the cutting edges of the knives 4 along their entire width. The slide 12 travels a distance equal to twice the length of the crank throw 14. Hence, the grinding wheels are alternately dressed since each wheel traverses its respective truing device 10 upon each reciprocation of the slide 12.

In the event one of the knives becomes mutilated, the slide 12 may be again adjusted and the diamond dressing points It} likewise adjusted until the nick or dent in the blade is removed. Both diamond dressing points 11} are now moved away from the grinding disc a distance of approximately 1 millimeter so that all of the knives 4 will be uniformly ground when the grinding wheels 20 are advanced so that the frame of the cutting drum is connected with the frame of the tobacco cutting machine without any intermediate arrangement of the spacing as the knives are in their correct position with respect to the counter knives. The trouble-free cutting of the knives 4 is adjusted by adjusting the sleeves 6 and diamond points 10.

This is an I What I claim is:

In a sharpening mechanism for a tobacco cutting machine having a rotary drum cutter and an elongated horizontal tobacco mouthpiece for feeding tobacco to said cutter, comprising, a supporting frame in which said rotary cutter drum is rotatably supported, a slide reciprocably mounted on said frame adjacent the rotary cutter drum for movement in a direction parallel to the axis of said drum, a cross slide on said first named slide movable toward and away from said cutter drum, a motor on said cross slide having an armature shaft projecting from each end thereof, a grinding wheel on each projecting end of said armature shaft, whereby reciprocation of said slide will permit said grinding wheels to traverse the knives on said rotary cutter drum to sharpen the same, and a truing device mounted on said supporting frame including a bracket arranged at each end of the drum in offset relation therefrom to permit rotation of said drum, a sleeve having an exterior thread engaging a corresponding interior thread provided in a bore in said bracket to permit axial adjustment of said sleeve, :1 bolt-like member serving as a diamond holder extending through said sleeve, means for securing said member against axial displacement in said sleeve but permitting rotative movement of said sleeve, said truing device being arranged diametrically opposite said mouthpiece with respect to said drum to permit the knives on said drum to be sharpened by the grinding wheels and to facilitate the truing of the grinding wheels after each stroke of said slide.

References Cited in the file of this patent UNITED STATES PATENTS Re. 12,534 Stewart et a1. Sept. 25, 1906 2,476,l77 Bloom et al, July 12, 1949 2,633,683 Klingens Apr. 7, 1953 2,690,777 Korber et al. Oct. 5, 1954 

